Likert Scale
Devendra
Research Scholar
Department of Studies in Library and Information Science, University of
Mysore, Mysore -570 006.
Dr. Rensis Likert
(1903 - 1981)
The original idea for the likert scale is found in Rensis Likert’s 1932 article in Archive of
psychology titled “ A technique for the measurement of Attitudes”. This idea was
expanded by Likert’s 1934 Journal of social psychology article titled “ A simple and
Reliable method of scoring the Thurstone Attitude Scales”.
What is Likert scale?
• It is a psychometric scale commonly involved in research
that employs questionnaires.
• It is the most widely used approach to scaling responses in
survey research.
• Likert scales are a non-comparative scaling technique and
are one-dimensional in nature.
• When responding to a Likert questionnaire item respondents
specify their level of agreement or disagreement on a
symmetric agree-disagree scale for a series of statements.
• Thus, the range captures the intensity of their feelings for a
given item, while the results of analysis of multiple items
reveals a pattern that has scaled properties of the kind Likert
identities
Five – point Likert item
Likert Scale
Difference
Likert item
•Likert item is considered symmetric or
balanced because there are equal amounts
of positive and negative positions.
•Often five ordered response levels are
used, although many psychometricians
advocate using seven or nine level, a recent
empirical study found that a 5 or 7 point
scale.
The format of a typical five-level Likert item
1. Strongly
disagree
2. Disagree
3. Neither agree
nor disagree
4. Agree
5. Strongly agree
Example:
Q.18.Please measure the following affirmative perceptions about your library OPAC and Web OPAC use .
Codes: 1-strongly disagree, 2- disagree, 3- neutral, 4-agree, 5- strongly agree
S/N
Affirmative perception statements
Codes
(i)
OPAC / Web OPAC was Easier to use than I expected
1
2
3
4
5
(ii)
It was Fun to use
1
2
3
4
5
(iii)
It was Easy to use
1
2
3
4
5
(iv)
It helped me in finding the documents faster
1
2
3
4
5
(v)
It is Very difficult to use
1
2
3
4
5
(vi)
It is Very confusing to use
1
2
3
4
5
(vii)
I found more items than expected
1
2
3
4
5
(viii)
I am comfortable with simple search
1
2
3
4
5
(ix)
I am comfortable complex/Advance search
1
2
3
4
5
(x)
I am comfortable quick search
1
2
3
4
5
(xi)
I am comfortable when using OPAC/Web OPAC
1
2
3
4
5
Q.19. Please mark your appreciation towards the use of your library OPAC/Web OPAC.
Codes: 1-strongly disagree, 2- disagree, 3- neutral, 4-agree, 5- strongly agree
S/N
Parameters
Codes
(i)
I access OPAC/Web OPAC stand alone system
1
2
3
4
5
(ii)
I access OPAC/Web OPAC library premises
1
2
3
4
5
(iii)
It is easy to be familiar with this OPAC/Web OPAC
1
2
3
4
5
(iv)
The OPAC/Web OPAC should have more flexible
interfaces
1
2
3
4
5
(v)
Library searching will be easier and faster with the Web
OPAC
1
2
3
4
5
(vi)
It is easy to read information provided in the Web OPAC
1
2
3
4
5
(vii)
A OPAC/Web OPAC search by author is easy
1
2
3
4
5
(viii)
A OPAC/ Web OPAC search by call number is easy
1
2
3
4
5
(ix)
OPAC/ Web OPAC scanning through a long display
(forward or backward) is easy
1
2
3
4
5
(x)
OPAC/ Web OPAC reducing the result when too much is
retrieved is easy
1
2
3
4
5
The format of a typical Seven-level Likert item
Analysis Methods
Depending on how the Likert scale questions are treated a number
of different analysis methods can be applied
1. Analysis methods used for individual questions (ordinal data)
 Bar charts and dot plots
• Not histograms (data is not continuous)
 Central tendency summarised by median and mode
• Not mean
 Variability summarised by range and interquartile range
• Not standard deviation
 Analysed using non-parametric tests
(difference between the medians of comparable groups)
• Mann- whitney U test
• Wilcoxon signed –rank test
• Kruskal – wallis test
2. When multiple Likert question responses are summed
together (interval data)
 All questions must use the same Likert scale
 Must be a defendable approximation to an interval
scale (i.e. coding indicates magnitude of difference
between items but there is no absolute zero point)
 All items measure are single latent variable (i.e. a
variable that is not directly observed, but rather
inferred from other variables that are observed and
directly measured)
 Analyzed using parametric tests
• Analysis of variance (ANOVA)
3. Analysis methods used when reduced to
nominal level of agree vs. disagree
 Chi –square test
 Cochran Q test
McNemar test
Advantages
• Item analysis increases the degree of
homogeneity or internal consistency in the set of
statements.
• Subjects generally find it easy to respond because
they have a wide range of answers(usually five) to
choose from instead of only two alternative
responses, i.e., agree or disagree.
• No outside group of judges is involved in
selecting statements and giving values to them.
Limitations
• Ties in ranks occur quite frequently.
• The response pattern of an individual is not
revealed.
• A respondent is required to answer all
questions on the scale.
• A problem of interpretation arises with this
type of scale.
• In this scale all statements of a universe are
deemed to be of equal attitude value.
Conclusion
A summated rating scale is a set of attitude statements
all of which subjects respond with degrees of
agreement or disagreement carrying different scores.
These scores are summed or summed and averaged to
yield an individual’s attitude score. The objective is to
avoid the use of only a single statement to represent a
concept and instead to use several statement as
indicators, all representing different facets of the
concept to obtain a more well rounded perspective.
Thank You